Optical fiber transmission systems are employed in data centers to optically connect one optical device (e.g., a router, a server, a switch, etc.) with one or more other optical devices.
Current data centers are typically configured with multimode optical fibers coupled to 850 nm multimode vertical-cavity surface-emitting laser (VCSELs) light sources that provide modulated data signals to the multimode fibers. Such multimode fibers are used because the light sources in the transceivers in the optical devices are multimode light sources. Historically, it has been easier to work with multimode fiber than single-mode fiber. Unfortunately, multimode fiber may have a smaller bandwidth-distance product due to modal dispersion, which may make it difficult and expensive to extend the reach of the optical fiber transmission system while maintaining high-bandwidth transmission. Furthermore, utilizing a typical transmitter (that utilizes an 850 nm VCSEL) operating at 10 Gb/s as a source, current standard optical multimode 3 (OM3) and optical multimode 4 (OM4) multimode optical fibers can transmit optical signals over a distance typically of only about 300 m to about 500 m, due to signal distortion caused by the modal dispersion and chromatic dispersion introduced by silica material of these multimode fibers. As optical transmission speed moves to 25 Gb/s or higher, this distance becomes even shorter (e.g., about 10 m to 100 m) for the current standard OM3 and OM4 multimode optical fibers operating at around 850 nm.